There are known to be image capture apparatuses in which an exit pupil of a shooting lens (imaging optical system) is divided into multiple pupil regions, and according to which multiple images that each correspond to one pupil region can be generated with one shooting operation (U.S. Pat. No. 4,410,804). These multiple images are images with parallax (parallax images), and therefore are pieces of information representing not only the spatial distribution but also the angular distribution of the light intensity, and have properties similar to data known as light field (LF) data and light space data.
Ren Ng et al, “Light Field Photography with a Hand-Held Plenoptic Camera”, Stanford Tech Report CTSR 2005-02, 2005 Apr. 20) discloses a refocus technique in which the in-focus position of the captured image is changed after shooting by using LF data to combine images in an imaging plane (virtual imaging plane) different from that at the time of shooting.
In the case of using a configuration in which a pupil region is divided using an image sensor with pixels each having multiple (n) divided photoelectric conversion regions, a maximum of n parallax images are generated with one shooting operation. For this reason, the amount of image data is that of n times the number of images that would have been generated if the pupil region was not divided. Furthermore, if an image corresponding to a normal image is generated by adding together the parallax images with consideration given to compatibility with a device that does not support parallax images, the amount of data corresponds to a factor of n+1.
If all of the parallax images and the normal image are stored by being included in one image file, the file size will be extremely large, the consumption amount of the storage medium will increase, the amount of time needed for reading and writing will increase, and battery consumption will increase. Also, if only the parallax images are stored, for example, there may also be a problem with file compatibility with apparatuses that do not support parallax images. This kind of problem occurs also when generating an image file containing data of images having a relationship between a part and the whole (or in which one image is generated from another image), as with the multiple parallax images (first images) and a normal image (second image).